A vehicle conventionally includes a suspension and a stabilizer, as disclosed in Japanese Patent Application Publication No. 2011-247338. The suspension includes an oil damper and a compression coil spring to reduce the impact transmitted from the road surface to the vehicle body.
The stabilizer uses a restoring force caused by torsional deformation of a bar to increase roll stiffness (rigidity against torsion) of the vehicle body. The suspension and the stabilizer are connected with each other via a stabilizer link. The stabilizer link is formed to have one connecting part to be fixed to the suspension and the other connecting part to be fixed to the stabilizer, which are arranged at both ends of a solid or hollow support bar.
Each of the connecting parts arranged at both ends of the support bar has a ball joint structure to include a ball stud and a housing for accommodating the ball stud. The housings of the connecting parts are integrally attached to both ends of the support bar. The housing is a member in a cup shape to accommodate a sphere part (ball part) of the ball stud so as to be slidable. The housing includes therein a resin supporting member (ball seat). The ball part of the ball stud is received by the ball seat so as to be slidable.
The ball part is slidable on the inner surface of the ball seat to allow the ball stud to be swingable and rotatable. The stabilizer link has a ball joint structure as described above in each of the connecting parts at both ends, to movably connect the suspension with the stabilizer.
For the ball stud smoothly swinging and rotating, the frictional force between the ball part and the ball seat is preferably maintained at a low value as designed. Here, the ball seat receiving the ball part is made of resin. Accordingly, the size largely varies at the time of molding to make it difficult for the frictional force between the ball part and the ball seat to be maintained.